111 results about "Electric field modulation" patented technology

A filtration device including a filtration medium having a plurality of nanofibers of diameters less than 1 micron formed into a fiber mat in the presence of an abruptly varying electric field. The filtration device includes a support attached to the filtration medium and having openings for fluid flow therethrough. A device for making a filter material. The device includes an electrospinning element configured to electrospin a plurality of fibers from a tip of the electrospinning element, a collector opposed to the electrospinning element configured to collect electrospun fibers on a surface of the collector, and an electric field modulation device configured to abruptly vary an electric field at the collector at least once during electrospinning of the fibers. A method for making a filter material. The method provides a support having openings for fluid flow therethrough, electrospins nanofibers across an entirety of the openings, and abruptly varies an electric field at the collector at least once during electrospinning of the fibers.

A variable optical device for controlling the propagation of light has a liquid crystal layer (1), electrodes (4) arranged to generate an electric field acting on the liquid crystal layer, and an electric field modulation layer (3,71) arranged between the electrodes and adjacent the liquid crystal layer for spatially modulating said electric field in a manner to control the propagation of light passing through said optical device. The electric field modulation layer has either an optical index of refraction that is essentially spatially uniform, or a polar liquid or gel, or a very high low frequency dielectric constant material having a dielectric constant greater than 20, and preferably greater than 1000. The modulation layer can have a solid body having a first low frequency dielectric constant with a shape selected to impart a desired modulation of the electric field, and a second low frequency dielectric constant material surrounding or adjacent to the solid body such that the solid body and the second material form a layer geometry.

A molecular system is provided for nanometer-scale reversible electronic and optical switches, specifically, electric field-activated molecular switches that have an electric field induced band gap change that occurs via a molecular conformation change or a tautomerization. Changing of extended conjugation via chemical bonding change to change the band gap is accomplished by providing the molecular system with one rotating portion (rotor) and two or more stationary portions (stators), between which the rotor is attached. The molecular system of the present invention has three branches (first, second, and third branches) with one end of each branch connected to a junction unit to form a "Y" configuration. The first and second branches are on one side of the junction unit and the third branch is on the opposite side of the junction unit. The first branch contains a first stator unit in its backbone, the junction unit comprises a second stator unit, and the first branch further contains a rotor unit in its backbone between the first stator unit and the second stator unit. The second branch includes an insulating supporting group in its backbone for providing a length of the second branch substantially equal to that of the first branch, wherein the rotor unit rotates between two states as a function of an externally-applied field.

The invention discloses a semiconductor device and a manufacturing method thereof. The semiconductor device comprises a substrate, a semiconductor layer located on the substrate, a source and a drain located on the semiconductor layer, a gate located between the source and the drain, a source field plate located on the semiconductor layer and connected with the source, wherein the source field plate passes across the gate, the gate/source region and part of the gate/drain region, and air isolation is carried out; one end of the source field plate is connected with the source; two or more than two metal field plates are connected in parallel to form connection between the source field plate and the source; and the other end of the source field plate is located on the semiconductor layer, close to the gate, between the gate and the drain. A role of electric field modulation of the source field plate can be fully played, parasitic gate/source capacitance and parasitic conduction resistance can be fully reduced, and reliability of the device is improved.

A method and apparatus for adjusting an electric field of an electrochemical processing cell are provided. In one embodiment, a capacitive element is disposed in the processing solution. The strength, shape, or direction of the electric field in the processing solution may be modulated by charging and discharging the capacitive element in a controlled manner. Because the electric field is modulated with out passing a current from the capacitive element to the processing solution, electrochemical reactions do not occur on the interface of the capacitive element and the processing solution, thus, reduces complications caused by unwanted electrochemical reactions.

The invention relates to the field of semiconductor devices and discloses a super junction lateral double diffusion metal oxide semiconductor (SJ-LDMOS) field effect transistor and a manufacturing method thereof. An active area of the SJ-LDMOS comprises a lateral super junction structure and a burying area formed below the lateral super junction structure. Due to the fact that the conduction types of the burying area and the semiconductor substrate are different, the semiconductor substrate and the burying area can assist depletion of an N-type column area and a P-type column area of the lateral super junction structure, load unbalance between the N-type column area and the P-type column area caused by the substrate auxiliary effect is supplemented, and high lateral breakdown voltage can be obtained. Meanwhile, a P junction and an N junction between the semiconductor substrate and the burying area lead a high electric field peak towards the surface of the semiconductor substrate and in the vertical direction, even lateral and vertical electric field distribution can be achieved through the electric field modulation effect, and higher lateral and vertical breakdown voltage can be obtained.

The invention discloses a step p-GaN enhanced AlGaN/GaN heterojunction field effect transistor. According to the transistor structure, a p type GaN cap layer is introduced into the transistor grid edge, and the thickness of the cap layer is smaller than that of a p type GaN dielectric layer under a grid. The p type GaN cap layer can lower the two-dimensional electron gas concentration of a conducting channel in the area, and the electric field modulation effect is achieved. By generating a new electric field peak, a high electric field at the grid edge is lowered, and electric field distribution on the surface of the transistor is more uniform. Compared with a traditional p-GaN enhanced structure, the step p-GaN enhanced AlGaN/GaN heterojunction field effect transistor is obviously raised and improved in the aspects of breakdown voltage and reliability.

The invention proposes an SJ-LDMOS (super-junction LDMOS (laterally double-diffused metal-oxide semiconductor) field effect transistor with double-electric-field modulation) with double-electric-field modulation. In the SJ-LDMOS, a partitioning part in a form of an epitaxial layer projection structure is formed between a buffering layer of SJ drift region and a trench, thereby enabling the edge of the buffering layer to modulate an SJ drift region electric field close to the trench. The length of a P column in the SJ drift region is less than the length of an N column, i.e., the P column being separated from a drain region, thereby preventing the connection of the P column with the drain region from generating a peak electric field, and enabling the edge of the buffering layer to modulate the SJ drift region electric field close to the drain region. Therefore, a part of buffering layer below the SJ drift region and the P column structure at the upper part of the SJ drift region are employed for the modulation of two electric fields at two parts of the drift region of a device, thereby enabling the surface electric field of the device to tend to be uniform, and greatly enlarging a breakdown voltage of the device under the condition of guaranteeing low on resistance of the device.

The invention discloses an AlGaN/GaN heterojunction field effect transistor with a partial P type GaN cap layer. According to the transistor structure, the P type GaN cap layer is introduced into the grid edge of the transistor and will reduce the two-dimensional electron gas concentration of a conducting channel of the region to achieve the electric field modulation effect. By generating a new electric field peak, high electric field of the grid edge is reduced, and the electric field on the surface of the transistor is more uniform. Compared with a traditional structure, the breakdown voltage and reliability of the field effect transistor are obviously improved.

The invention discloses a p-GaN enhanced AlGaN/GaN high-electron-mobility transistor with a partially intrinsic GaN cap layer. According to the transistor structure, the intrinsic GaN cap layer is introduced into a transistor grid electrode and the edge of a p type GaN medium layer of the transistor grid electrode, the two-dimensional electron gas concentration of a conducting channel in the area can be reduced by means of the intrinsic GaN cap layer, and the electric field modulation effect is achieved. A new electric field peak is generated, so that the high electric field of the grid edge is reduced, and an electric field on the surface of the transistor is distributed more evenly. Compared with a traditional p-GaN enhanced structure, the breakdown voltage and reliability of the novel structure are obviously improved.

Disclosed are a novel electric field modulation type memory cell array and a random memory, wherein the memory comprises the novel electric field modulation type memory cell array and a corresponding read-write circuit. The memory cells in the memory cell array can use a structure of conducting layers, function layers and base layers or a structure of conducting layers, insulation layers, buffer layers, function layers and base layers. Both the structures are provided with two data reading lines and two data writing lines. The memory cells in the novel electric field modulation type memory cell array also can use a structure combined with a transistor and utilize the transistor to select memory cells. The random memory comprises a decoder of elementary rows, a sense amplifier, a decoder of columns, a register, a control circuit, a read-write driver, an input interface, an output interface and the like. The novel random memory has the advantages of being simple in structure, long in service life of components, low in power consumption and the like.

The invention discloses a novel GaN heterojunction field effect transistor. According to the invention, a P-type GaN buried layer is introduced into a local area of a GaN channel layer of a field effect transistor. The P-type GaN buried layer can improve the heterojunction energy band of the area so as to reduce local channel 2-DEG concentration and a pn junction field board is introduced into theGaN channel layer along the current direction so as to modulate channel electric field. According to the invention, P-type GaN buried layer and groove technology are combined together, so that a threshold value voltage regulation scheme becomes more flexible and threshold value voltage regulation of a larger range can be realized. At the same time, by the electric field modulation effect of the P-type GaN buried layer in the GaN channel layer, the maximal peak value electric field in a device can be reduced effectively and electric field distribution uniformity can be improved. Besides, the P-type GaN buried layer introduces a barrier in a GaN Buffer, so that source and drain electrode punchthrough of the device caused by Buffer electric leakage can be inhibited effectively. Therefore, compared with a traditional groove gating GaN heterojunction field effect transistor, the new structure enlarges the threshold value voltage regulation range effectively and improves the voltage resistance of the device substantially.

The invention discloses a VDMOS device with a variable dielectric side. A new electric field peak is generated by sequentially filling side layers formed by dielectrics with different dielectric constants (K value), the field distribution of VDMOS high resistance drift region is modulated, and the lateral electric field modulation effect is enhanced, so that high-density doping can be conducted on the drift region. Under same breakdown voltage conditions, the structure makes the VDMOS have lower specific on-resistance. The novel structure can increase the breakdown voltage of the device and lower the conduction resistance of the power device. A new technology breaking the silicon limit of a power device is provided.

The invention provides an LDMOS (laterally diffused metal oxide semiconductor) field effect transistor with a bulk electric field modulation function. The LDMOS field effect transistor has the characteristic that a wide bandgap semiconductor SiC (silicon carbide) burying layer is formed under the drain end of the LDMOS field effect transistor by a heteroepitaxy technique; an internal high peak electric field under the drain end is led into the SiC burying layer, the characteristic of higher critical breakdown electric field (EC-SiC=3.0*106V/cm greater than EC-Si=3.0*105V/cm) of the SiC material is utilized, and the breakdown occurs in the SiC burying layer, so that the breakdown voltage of the LDMOS is effectively increased, and the property of the LDMOS field effect transistor is greatly improved.

The invention provides a broad-band gap semiconductor vertical double diffusion metal oxide semiconductor field effect transistor having a composite dielectric layer and a manufacturing method thereof. The device is characterized in that the composite dielectric layer is formed by a semi-insulation polysilicon layer (SIPOS) and a high dielectric constant (High K) dielectric layer at a drift region side wall below a device gate electrode. When the device is turned off, the SIPOS column and the High K dielectric layer have uniform electric fields, electric distribution in the drift region of the device is made to be uniform through electric field modulation, moreover, exhaust of the drift region is commonly facilitated by the SIPOS column and the High K dielectric layer, exhaust capability of the device drift region is substantially improved, drift region doping concentration of the device is made to increase, and conduction resistance is reduced; when the device is turned on, the side wall of the drift region has multiple carrier accumulation layers, and conduction resistance of the device is reduced further.

The invention provides a laminated electric field modulation high-voltage MOSFET structure and a method for manufacturing the same. The MOSFET structure includes a semiconductor substrate provided with the epitaxial layer of a laminated electric field modulation structure and the metal-oxide-semiconductor (MOS) structure on the laminated electric field modulation. The laminated electric field modulation is an N/P/N/P structure composed of alternate n-type semiconductors and p-type semiconductors. The N/P structure and the semiconductor substrate have the same material. The N-doped region and the P-doped region in the layer are aligned to each other. The invention provides different methods for manufacturing the electric field modulation structure, including a high-energy ion implantation method, an etching deep groove and filling method, and an etching deep groove and sidewall ion implantation method, thereby laying the foundation for the fabrication of a device. The MOSFET obtained by the technical scheme in the invention not only inherits advantages of increasing blocking voltage and decreasing on-resistance of a traditional semi-super junction structure, but also reduces the difficulty of processing technology of each electric field modulation structure layer.

The invention provides an SBD device and a manufacturing method thereof. The SBD device comprises an ohmic contact metal layer, a substrate, an epitaxial layer, a first passivation layer and a secondpassivation layer, wherein the substrate is located on the ohmic contact metal layer; the epitaxial layer is positioned on the substrate; the first passivation layer is located on the epitaxial layer;the metal layer is located on the first passivation layer; and the second passivation layer is positioned on the metal layer. By using the SBD device and the manufacturing method thereof, a multi-step field plate structure is introduced into a vertical Ga2O3 SBD device so that an electric field aggregation effect at steps is solved, an electric field modulation effect is improved, a breakdown voltage of the device is increased, an electric field peak value of the device is pulled into the device from a surface, and a leakage current of the device is reduced.

The invention relates to an X-ray source for spatial X-ray communication based on energy load signals; a cathode assembly of the X-ray source comprises an electron emission source, a power supply rod,power supply rod insulation ceramic, a cathode cover and a cathode barrel; a focusing electrode assembly comprises a focusing electrode diaphragm and a focusing electrode barrel; an anode assembly comprises an anode diaphragm and an anode barrel and is connected with a multi-target transmission window assembly through the anode barrel; an electric field modulation assembly comprises a multi-section electrode and an electrode bracket; and the multi-target transmission window assembly comprises metal target materials, a transmission window and a target welding ring. According to the X-ray source for spatial X-ray communication based on energy load signals in the invention, a fast-response high-frequency pulse modulation electric field modulation assembly is utilized to generate a modulationelectric field, the electronic motion track is changed, the different metal target materials on the multi-target transmission window assembly are bombarded, and characteristic X-rays with different energy are generated. The characteristic X-rays with various kinds of energy are used as code elements, so that rapid X-ray spatial communication based on energy load signals is achieved. The X-ray source in the invention is high in modulation speed, large in number of the loadable code elements, high in signal-to-noise ratio, low in error rate and high in communication speed.

The invention provides a transistor and a preparation method thereof, belongs to the technical field of transistors (especially gallium nitride transistors) and is capable of at least partially solving the problems of characteristic degradation and poor reliability of an existing transistor provided with a P-type cap layer along with use. The transistor provided by the invention comprises superimposed channel layer and barrier layer, a source, a drain and a gate, wherein the source, the drain and the gate are arranged at one side, far away from the channel layer, of the barrier layer at intervals; the gate is located between the source and the drain; the P-type cap layer is arranged between the gate and the barrier layer; schottky contact is formed between the P-type cap layer and the gate; two side edge areas, close to the source and the drain, of the P-type cap layer are two interspaced electric field modulation areas; and the electric field modulation areas can induce positive charges under positive gate-source voltage.

The invention relates to the technical field of semiconductors, and discloses a split-gate MOS device and a preparation method thereof. The split-gate MOS device comprises a substrate, a first epitaxial layer, a second epitaxial layer and a third epitaxial layer of a first conduction type are sequentially arranged on the substrate from bottom to top, the doping concentration of the second epitaxial layer is greater than that of the first epitaxial layer, the doping concentration of the first epitaxial layer is larger than that of the second epitaxial layer, the doping concentration of the second epitaxial layer is larger than that of the third epitaxial layer, and the first epitaxial layer, the second epitaxial layer and the third epitaxial layer form a drift region of the split-gate MOS device. Firstly, the second epitaxial layer with high doping concentration can enhance the electric field modulation effect of the drift region and increase the withstand voltage of the split-gate MOS device; secondly, electric field lines can be prevented from being accumulated on two sides of the bottom of the groove, and the split-gate MOS device is prevented from being broken down on two sides of the bottom of the groove in advance when withstanding voltage; and thirdly, the on-resistance of the device is reduced.